scholarly journals Peroxisome Proliferator-Activated Receptor γ and Adipose Tissue—Understanding Obesity-Related Changes in Regulation of Lipid and Glucose Metabolism

2006 ◽  
Vol 92 (2) ◽  
pp. 386-395 ◽  
Author(s):  
Arya M. Sharma ◽  
Bart Staels
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Endocrine Function ◽  
Low Grade ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor

Abstract Context: Adipose tissue is a metabolically dynamic organ, serving as a buffer to control fatty acid flux and a regulator of endocrine function. In obese subjects, and those with type 2 diabetes or the metabolic syndrome, adipose tissue function is altered (i.e. adipocytes display morphological differences alongside aberrant endocrine and metabolic function and low-grade inflammation). Evidence Acquisition: Articles on the role of peroxisome proliferator-activated receptor γ (PPARγ) in adipose tissue of healthy individuals and those with obesity, metabolic syndrome, or type 2 diabetes were sourced using MEDLINE (1990–2006). Evidence Synthesis: Articles were assessed to provide a comprehensive overview of how PPARγ-activating ligands improve adipose tissue function, and how this links to improvements in insulin resistance and the progression to type 2 diabetes and atherosclerosis. Conclusions: PPARγ is highly expressed in adipose tissue, where its activation with thiazolidinediones alters fat topography and adipocyte phenotype and up-regulates genes involved in fatty acid metabolism and triglyceride storage. Furthermore, PPARγ activation is associated with potentially beneficial effects on the expression and secretion of a range of factors, including adiponectin, resistin, IL-6, TNFα, plasminogen activator inhibitor-1, monocyte chemoattractant protein-1, and angiotensinogen, as well as a reduction in plasma nonesterified fatty acid supply. The effects of PPARγ also extend to macrophages, where they suppress production of inflammatory mediators. As such, PPARγ activation appears to have a beneficial effect on the relationship between the macrophage and adipocyte that is distorted in obesity. Thus, PPARγ-activating ligands improve adipose tissue function and may have a role in preventing progression of insulin resistance to diabetes and endothelial dysfunction to atherosclerosis.

scholarly journals Peroxisome Proliferator–Activated Receptors and The Metabolic Syndrome

2009 ◽  
Vol 1 (1) ◽  
pp. 4 ◽  
Author(s):  
Anna Meiliana ◽  
Andi Wijaya
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Energy Balance ◽  
Glucose Homeostasis ◽  
Gene Activation ◽  
Sugar Metabolism ◽  
Endocrine Function ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
The Metabolic Syndrome

BACKGROUND: Obesity is a growing threat to global health by virtue of its association with insulin resistance, inflammation, hypertension, and dyslipidemia, collectively known as the metabolic syndrome (MetS). The nuclear receptors PPARα and PPARγ are therapeutic targets for hypertriglyceridemia and insulin resistance, respectively, and drugs that modulate these receptors are currently in clinical use. More recent work on the PPARδ has uncovered a dual benefit for both hypertriglyceridemia and insulin resistance, highlighting the broad potential of PPARs in the treatment of metabolic disease.CONTENT: We have learned much about PPARs, the metabolic fat sensors, and the molecular pathways they regulate. Through their distinct tissue distribution and specific target gene activation, the three PPARs together control diverse aspects of fatty acid metabolism, energy balance, insulin sensitivity glucose homeostasis, inflammation, hypertension and atherosclerosis. These studies have advanced our understanding of the etiology for the MetS. Mechanisms revealed by these studies highlight the importance of emerging concepts, such as the endocrine function of adipose tissue, tissue-tissue cross-talk and lipotoxicity, in the pathogenesis of type 2 diabetes mellitus and CVD.SUMMARY: The elucidation of key regulators of energy balance and insulin signaling have revolutionized our understanding of fat and sugar metabolism and their intimate link. The three ‘lipidsensing’ (PPARα, PPARγ and PPARδ) exemplify this connection, regulating diverse aspects of lipid and glucose homeostasis, and serving as bonafide therapeutic targets.KEYWORDS: Peroxisome Proliferator, Activated Receptor, Metabolic Syndrome

scholarly journals Whey Peptides Stimulate Differentiation and Lipid Metabolism in Adipocytes and Ameliorate Lipotoxicity-Induced Insulin Resistance in Muscle Cells

Nutrients ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 425 ◽  
Author(s):  
Kenneth D’Souza ◽  
Angella Mercer ◽  
Hannah Mawhinney ◽  
Thomas Pulinilkunnil ◽  
Chibuike C. Udenigwe ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Lipid Metabolism ◽  
Milk Proteins ◽  
C2c12 Myotubes ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Systemic Insulin Resistance ◽  
Skeletal Myotubes

Deregulation of lipid metabolism and insulin function in muscle and adipose tissue are hallmarks of systemic insulin resistance, which can progress to type 2 diabetes. While previous studies suggested that milk proteins influence systemic glucose homeostasis and insulin function, it remains unclear whether bioactive peptides generated from whey alter lipid metabolism and its accumulation in muscle and adipose tissue. Therefore, we incubated murine 3T3-L1 preadipocytes and C2C12 myotubes with a whey peptide mixture produced through pepsin-pancreatin digestion, mimicking peptides generated in the gut from whey protein hydrolysis, and examined its effect on indicators of lipid metabolism and insulin sensitivity. Whey peptides, particularly those derived from bovine serum albumin (BSA), promoted 3T3-L1 adipocyte differentiation and triacylglycerol (TG) accumulation in accordance with peroxisome proliferator-activated receptor γ (PPARγ) upregulation. Whey/BSA peptides also increased lipolysis and mitochondrial fat oxidation in adipocytes, which was associated with the upregulation of peroxisome proliferator-activated receptor δ (PPARδ). In C2C12 myotubes, whey but not BSA peptides ameliorated palmitate-induced insulin resistance, which was associated with reduced inflammation and diacylglycerol accumulation, and increased sequestration of fatty acids in the TG pool. Taken together, our study suggests that whey peptides generated via pepsin-pancreatin digestion profoundly alter lipid metabolism and accumulation in adipocytes and skeletal myotubes.

scholarly journals Pioglitazone in the Treatment of Type 2 Diabetes: Safety and Efficacy Review

2010 ◽  
Vol 3 ◽  
pp. CMED.S5372 ◽  
Author(s):  
Cyrus V. Desouza ◽  
Vijay Shivaswamy
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Ppar Gamma ◽  
New Drugs ◽  
Peroxisome Proliferator ◽  
Cardiovascular Safety ◽  
Peroxisome Proliferator Activated Receptor ◽  
Safety And Efficacy ◽  
Beneficial Effects

The increase in obesity and the aging of the population has lead to an increase in the incidence of type 2 diabetes. This has led to the development of new drugs such as thiazolidinediones (TZDs) which are Peroxisome Proliferator-Activated Receptor (PPAR-gamma) agonists, to treat type 2 diabetes. TZDs have recently been at the center of a controversy with regards to their cardiovascular safety. Pioglitazone is a TZD which has been shown to be effective in glycemic control by lowering insulin resistance. Pioglitazone also has beneficial effects on lipid metabolism and cardiovascular risk. The safety and efficacy of pioglitazone including its pleotropic effects are discussed at length in this article.

scholarly journals Fatty acid metabolism in obesity and type 2 diabetes mellitus

2003 ◽  
Vol 62 (3) ◽  
pp. 753-760 ◽  
Author(s):  
E. E. Blaak
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Skeletal Muscle ◽  
Type 2 Diabetes Mellitus ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Acid Oxidation ◽  
Acid Uptake

Disturbances in pathways of lipolysis and fatty acid handling are of importance in the aetiology of obesity and type 2 diabetes mellitus. There is evidence that a lowered catecholamine-mediated lipolytic response may play a role in the development and maintenance of increased adipose tissue stores. Increased adipose tissue stores, a disturbed insulin-mediated regulation of lipolysis and subnormal skeletal muscle non-esterified fatty acid (NEFA) uptake under conditions of high lipolytic rate may increase circulating NEFA concentrations, which may promote insulin resistance and cardiovascular complications. In addition, a disturbance of NEFA uptake by adipose tissue postprandially is also a critical determinant of plasma NEFA concentration. Furthermore, evidence is increasing that insulin-resistant muscle is characterised by a lowered ability to oxidise fatty acids. A dysbalance between fatty acid uptake and fatty acid oxidation may in turn be a factor promoting accumulation of lipid intermediates and triacylglycerols within skeletal muscle, which is strongly associated with skeletal muscle insulin resistance. The present review describes the reported disturbances in pathways of lipolysis and skeletal muscle fatty acid handling, and discusses underlying mechanisms and metabolic consequences of these disturbances.

scholarly journals Chiglitazar Preferentially Regulates Gene Expression via Configuration-Restricted Binding and Phosphorylation Inhibition of PPARγ

PPAR Research ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
De-Si Pan ◽  
Wei Wang ◽  
Nan-Song Liu ◽  
Qian-Jiao Yang ◽  
Kun Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Glucose And Lipid Metabolism ◽  
Effective Part

Type 2 diabetes mellitus is often treated with insulin-sensitizing drugs called thiazolidinediones (TZD), which improve insulin resistance and glycemic control. Despite their effectiveness in treating diabetes, these drugs provide little protection from eminent cardiovascular disease associated with diabetes. Here we demonstrate how chiglitazar, a configuration-restricted non-TZD peroxisome proliferator-activated receptor (PPAR) pan agonist with moderate transcription activity, preferentially regulates ANGPTL4 and PDK4, which are involved in glucose and lipid metabolism. CDK5-mediated phosphorylation at serine 273 (S273) is a unique regulatory mechanism reserved for PPARγ, and this event is linked to insulin resistance in type 2 diabetes mellitus. Our data demonstrates that chiglitazar modulates gene expression differently from two TZDs, rosiglitazone and pioglitazone, via its configuration-restricted binding and phosphorylation inhibition of PPARγ. Chiglitazar induced significantly greater expression of ANGPTL4 and PDK4 than rosiglitazone and pioglitazone in different cell models. These increased expressions were dependent on the phosphorylation status of PPARγ at S273. Furthermore, ChIP and AlphaScreen assays showed that phosphorylation at S273 inhibited promoter binding and cofactor recruitment by PPARγ. Based on these results, activities from pan agonist chiglitazar can be an effective part of a long-term therapeutic strategy for treating type 2 diabetes in a more balanced action among its targeted organs.

scholarly journals Mechanisms of the components of the metabolic syndrome that predispose to diabetes and atherosclerotic CVD

2007 ◽  
Vol 66 (1) ◽  
pp. 82-95 ◽  
Author(s):  
Robert H. Eckel
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Fatty Acid ◽  
Inflammatory Cytokines ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
The Metabolic Syndrome ◽  
Pro Inflammatory Cytokines

The metabolic syndrome represents a summation of obesity-driven risk factors for atherosclerotic CVD and type 2 diabetes. Definitions of the syndrome vary but in general agree closely in identifying subjects. The relationships between the metabolic syndrome and atherosclerotic CVD and diabetes also vary, with relative risks of approximately 1·5–3·0 and approximately 3·0–5·0 respectively. Insulin resistance appears to explain much of the pathophysiology of the syndrome. Both increased fatty acid flux and an excess of circulating pro-inflammatory cytokines are likely mediators. With increased waist circumference, increases in fatty acid delivery to the liver result in higher rates of hepatic glucose production and increases in the secretion of apoB-containing lipoproteins. Concomitant changes in HDL ensue, including a replacement of the cholesterol content with TAG, an accelerated clearance from the plasma and thus a reduced number of HDL particles. Typically also present are increases in small dense LDL. Hypertension in part relates to the insulin resistance, but may involve other mechanisms. Impaired fasting glucose often relates to defects in insulin secretion in addition to insulin resistance, and probably more than any other component of the syndrome predicts the increased incidence of type 2 diabetes. Although not included in the diagnostic criteria, increases in pro-inflammatory cytokines and pro-thrombotic factors, in addition to decreases in plasma adiponectin, may also contribute to the increased incidence of atherosclerotic CVD and diabetes. In general, the greater the number of metabolic syndrome components, the greater the risk for these outcomes. The cytokines and pro-thrombotic factors also appear to contribute.

scholarly journals Molecular and cellular mechanisms of adipogenesis

2015 ◽  
Vol 18 (2) ◽  
pp. 12-19 ◽  
Author(s):  
Alexander Dmitrievich Egorov ◽  
Dmitry Nikolaevich Penkov ◽  
Vsevolod Arsen'evich Tkachuk
Keyword(s):  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Transcription Factors ◽  
Drug Targets ◽  
Adenosine Monophosphate ◽  
Endocrine Function ◽  
Peroxisome Proliferator ◽  
Cellular Mechanisms ◽  
Peroxisome Proliferator Activated Receptor ◽  
The Impact

The main components of metabolic syndrome include insulin resistance, hypertriglyceridemia and arterial hypertension. Obesity is the cause of metabolic syndrome, mainly as a consequence of the endocrine function of adipose tissue. The volume of adipose tissue depends on the size of individual adipocytes and on their number. The number of adipocytes increases as a result of enhanced adipocyte differentiation. The transcriptional cascade that regulates this differentiation has been well studied. The major adipogenic transcription factor peroxisome proliferator-activated receptor gamma is a ligand-activated nuclear receptor with essential roles in adipogenesis. Its ligands are used to treat metabolic syndrome and type 2 diabetes mellitus. . The present article describes the basic molecular and cellular mechanisms of adipogenesis and discusses the impact of insulin, glucocorticoids, cyclic adenosine monophosphate-activating agents, nuclear receptors and transcription factors on the process of adipogenesis. New regulatory regions of the genome that are capable of binding multiple transcription factors are described, and the most promising drug targets for the treatment of metabolic syndrome and obesity, including the homeodomain proteins Pbx1 and Prep1, are discussed..

The combination of insulin resistance and visceral adipose tissue estimation improves the performance of metabolic syndrome as a predictor of type 2 diabetes

2020 ◽  
Vol 37 (7) ◽  
pp. 1192-1201 ◽  
Author(s):  
N. E. Antonio‐Villa ◽  
O. Y Bello‐Chavolla ◽  
A. Vargas‐Vázquez ◽  
R. Mehta ◽  
C. A. Aguilar‐Salinas ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Metabolic Syndrome ◽  
Adipose Tissue ◽  
Visceral Adipose Tissue ◽  
Visceral Adipose
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